Equal parts and equivalent fractions

In Primary 2, four equal parts give denominator four, and three shaded parts give numerator three. Today we learn about equivalent fractions. Here is today's question. Complete the equivalent fractions. Three sevenths is equal to how many twenty-eighths? What is the missing numerator? Here is a kueh lapis, drawn as a bar. This bar is one whole. Cut it into seven equal parts. The denominator is seven. Shade three parts. The numerator is three. We write today's question on our page. Twenty-eighths means the same whole cut into twenty-eight equal parts. So how many small parts must each part become? Twenty-eight divided by seven is four. We copy the bar below, with its shading. Cut each part into four equal parts. Seven times four is twenty-eight. The shaded part must stay the same. Three times four is twelve. Check on the bar. Count in fours: four, eight, twelve. So three sevenths is equal to twelve twenty-eighths. The whole did not change. The shaded part did not change. So the missing numerator is twelve. Multiply or divide the numerator and the denominator by the same number.

Kavin ate two thirds of a kueh lapis. Complete the equivalent fractions. Two thirds is equal to how many ninths? What is the missing numerator? Try it first. Pause if you like. Here is the kueh lapis as a bar. It is one whole. It is cut into three equal parts. The denominator is three. Shade the two parts Kavin ate. The numerator is two. Ninths means nine equal parts in the same whole. Nine divided by three is three. We copy the bar below, with its shading. Now we cut each part into three equal parts. Three times three is nine. Each shaded part now has three small parts. Two times three is six. Check on the bar. Count in threes: three, six. So two thirds is equal to six ninths. The missing numerator is six.

An egg roll is cut into twelve equal slices. Nine slices are eaten. Complete the equivalent fractions. Nine twelfths is equal to three parts out of how many equal parts? What is the missing denominator? Try it first. Pause if you like. Here is the egg roll as a bar. It is one whole. It is cut into twelve equal parts. The denominator is twelve. Shade the nine parts that are eaten. The numerator is nine. The numerator must change from nine to three. How many parts go into each new part? Nine divided by three is three. So we group the parts in threes. Nine divided by three gives numerator three. We must divide the denominator by three too. Twelve divided by three is four. Check on the bar: one, two, three, four groups. We copy the bar below. Each group of three becomes one bigger part. So nine twelfths is equal to three quarters. The missing denominator is four. Equivalent fractions are the same part of one whole.